After more than two weeks of confusion, I'm pleased to report a semi-successful test.
I say 'semi', because I didn't fry anything, but not all the motors are working as expected.
My X-axis is working fine, but is opposite the software control. When jogging in X to my left (-X, in the software) the print head moves to the right, and vice-versa.
The Y axis isn't moving at all. I suspect that the wiring diagram is not correct or I miss mis-wired the green union block. Surprising, since i took pains to get it right. Could be i screwed the pooch, but either case, this is important and could benefit from more clarity for dummies like me who don't grock electronics.
The Z axis is working, but when raising, skipping teeth on the belt, probably because of a miaalignment. suspect I'll have to realign the rods. There has to be a better way to do this. Perhaps a set of removable printed spacers to keep the brackets centered in their holes might be a way to go?
Anyway, just another two cents to help improve the WIP manual.